(1) Field of the Invention
The present invention relates to an electrosurgical apparatus mainly intended for the coagulative treatment, typically preliminary to resection, employing a plurality of electrodes connected to one or more generators and to a corresponding method.
(2) Description of Related Art Including Information Disclosed under 37 C.F.R. §1.97 and 1.98
In order to reduce or eliminate bleeding during and after a resective treatment of parenchymatous organs like liver, spleen, kidney, and so on, there are used apparatuses employing one or more generators, with a working frequency typically ranging from 200 kHz to 2 MHz, powering a plurality of electrodes, preferentially arranged in-line, in a bipolar mode. In particular, in said arrangement adjacent electrodes are connected to opposite poles of a generator, as schematically illustrated in FIG. 1, where the generator has been denoted by G. Therefore, between said adjacent electrodes there onset, through the tissue interposed thereamong, electrosurgical currents, denoted e.g. by I1 and I2 in FIG. 1, which flow into each intermediate electrode E. Optionally, the above-described configuration may employ a so-called “comb” electrode instead of a plurality of separate electrodes. Such a configuration is used, for example, to carry out linear or polygonal resections for the removal of damaged or diseased biological tissues, and in particular for the hepatic resection of tumours.
As mentioned above, due to the bipolar powering mode of the electrodes connected to the generator, at each intermediate electrode E there flow the currents passing in the two adjacent tissue segments. This increases the current density in the neighbourhood of the electrode E itself and therefore the likelihood of its producing a rapid drying of the surrounding tissue. When this occurs, the impedance of the tissue in the neighbourhood of the electrode increases, thereby impeding the current to continue to flow; the current accordingly ceases in the intervals comprised between the intermediate electrode E and the adjacent electrodes. Hence, the entire region surrounding the electrode E itself, schematically denoted by RE in FIG. 1, becomes totally “isolated” from the electrocoagulation process under way, though actually the treatment has not been completed in correspondence of the entire extension of said region, but merely in close proximity of the electrode E and not yet in the zones farthest therefrom.
Moreover, the excessive drying in the neighbourhood of the internal electrodes produces a strong adhesion of the tissue surrounding them, making difficult their retraction from the coagulated tissue.
Due to the foregoing, it is often necessary to employ electrodes very close one to the other.
The present invention is based just on the detection of the hereto-described drawbacks.
Hence, the technical problem set and solved by the present invention is to provide an apparatus for electrosurgery and a related method enabling to overcome the drawbacks mentioned above with reference to the known art.
Such a problem is solved by an apparatus according to claim 1.
According to the same inventive concept, the present invention further relates to a method according to claim 26.
Preferred features of the present invention are present in the dependent claims thereof.
The present invention provides several relevant advantages.
The main advantage lies in that, thanks to the incremental powering of the electrodes, the invention enables to keep a current flow through tissues even when the intermediate electrode is deactivated, as it will be better understood from the following detailed description.
Moreover, current in the inter-electrodes intervals being equal, the current density and therefore the overheating in the neighbourhood of each electrode is markedly decreased.
All this enables to carry out a more effective electrosurgical treatment and to attain a more uniform result. Moreover, it is possible to reduce the number of electrodes employed, or anyhow, results being equal, to arrange them at a greater mutual distance with respect to the known art.